中文摘要：

目的探讨广西扶绥县肝癌高发区壮族人群谷胱甘肽转硫酶GSTM1和GSTT1的基因多态性在肝癌家族聚集性中的作用，以及一级亲属与先证者之间HCC易感性的关系。方法采用病例一对照研究方法，收集21个广西扶绥县壮族肝癌家系76例，以及该地区21个对照家系68例，采用多重PCR技术和凝胶成像分析方法，对入选者GSTM1和GSTT1基因型进行检测，用ELISA法检测HBsAg，并将实验结果与临床资料相结合，进行统计学分析。结果（1）GSTM1基因空白型在肝癌家系组、对照家系组之间的频率分别为67．1％和36．8％（P=0．000）；GSTT1基因空白型在肝癌家系组、对照家系组之间的频率分别为40．8％和19．1％（P=-0．005）；GSTM1和GSTT1基因同时缺失在肝癌家系组、对照家系组的频率分别为31．6％和2．9％（P=0．000）。②将GSTM1及GSTT1基因同时表达型为基准计算两基因联合作用的危险度，GSTM1基因缺失GSTT1基因表达型、GSTM1基因表达GSTT1基因缺失型、GSTM1基因及GSTT1基因联合缺失型的OR值分别为0．102、0．210和3．092。（3）GSTM1基因空白型在先证者与其直系亲属之间的频率分别为71．4％和65．5％（P=0．620），GSTT1基因空白型在先证者与其直系亲属之间的频率分别为47．6％和38．2％（P=0．454）。GSTM1和GSTT1基因同时缺失在先证者与其直系亲属之间的频率分别为33．3％和30．9％（P=-0．839），差异均无统计学意义（P〉0．05）。结论（1）GSTM1和GSTT1基因的多态性与肝癌家族聚集性相关；（2）GSTM1和GSTT1基因联合缺失与HCC的发生呈显著正相关，且两基因可能具有协同作用；③直系亲属与先证者HCC发生率无差别。

英文摘要：

Objective To study the relationship between family clustering of hepatocellular carcinoma（HCC ）and glutathione S-transferase M1 and T1 polymorphisms,to explore gene-gene interactions in HCC,and to assess differences in HCC risk between probands and first-degree relatives. Methods Peripheral blood samples were collected from 76 members of 21 HCC-clustefing families and 68 members of 21 control families in the Zhuang population of Fusui county, Guangxi province.This area has a high incidence of HCC.M1 and T1 genotypes were determined by multiplex polymerase chain reaction,and serum HBsAg was measured by ELISA. Genotypes and clinical data were analyzed statistically to search for associations. Results The frequency of the GSTM1 null genotype was 67.1% in the family consteUation of the HCC group and 36.8% in controls（P= 0.000）.The frequency of the GSTT1 null genotype was 40.8% in the family constellation of the HCC group and 13.2 % in controls（P= 0.005 ）,while the prevalence of the combined GSTM1 and GSTT1 null genotype was 31.6% and 2.9%（P=0.000）.Frequencies of the GSTMI or GSTT1 null genotype and of the combined GSTM1 and GSTT1 null genotype did not differ significantly between probands and first-degree relatives. Conclusions （1）A relationship was found between familial clustering of HCC and frequencies of the GSTM1 and GSTT1 polymorphisms. （2）A combined null genotype at GSTM1 and GSTT1 positively correlated with liver cancer occurrence,and it interacted synergistically with hepatocarcino-genesis.（3）The risk of HCC between first-degree relatives and probands is not significantly different.